Indicator device



Dec. '11, 1945.

P.- 5. DE BEAUMONT 2,390,643

INDICATOR DEVICE Original Filed Oct. 15, 1941 /a w k I N V EN TOR. Eer/"e 52, la/f defieqa mi in the engine sump,

Patented Dec. 11, 1945 INDICATOR DEVICE Pierre Stuart de Beaumont,Washington, D. C., assignor to Packard Motor Car Company, De-

troit, Mich., a corporati on of Michigan Original application October15, 1941, Serial No.

415,064. Divided and this application November 8, 1943, Serial No.509,417

' 4 Claims.

This invention relates to systems employing a Bourdon tube and is adivision of Patent No. 2,351,408 issued June 13, 1944.

An object of the invention is to provide a bimetallic tube that willreact to pressure and temperature.

Another object of the invention is to provide a Bourdon tube with acontact member for controlling an electric circuit.

Another object of the invention is to provide an indicator systemcontrolled by a bimetallic Bourdon tube in series with a fluid systemand reacting to the temperature and pressure of the fluid passingtherethrough.

Another object of the invention is to provide a switch member for anelectric circuit comprising a Bourdon tube with a contact at its freeend.

Other objects of the invention will appear from the followingdescription taken in connection with the drawing, which forms a part ofthis specification, and in which:

Fig. 1 is a partly broken away and sectioned elevational view of theforward end of a motor vehicle having an indicator system incorporatingthe invention associated therewith;

Fig. 2 is a diagrammatic view of the indicator system;

Fig. 3 is a sectional view of the indicator system control structuretaken on line 3-3 of Fig. 2.

In the drawing, an engine is shown in advance of a motor vehicle dash IIand instrument board 12. A conventional lubricating system supplies oilunder pressure to the usual engine bearings and includes a gear pump 13driven by the engine through shaft 14. The pump lies formed by pan l5,and has a strainer I 6 at the oil inlet end. The pump draws oil from thesump through the strainer and delivers it under pressure to adistributing manifold conduit 18 leading to engine bearings, such asbearings 11 for the crankshaft 9. Oil drains from the bearings into thesump and is recirculated by the pump.

Operating conditions of the engine and the lubricating system can bereadily ascertained by the vehicle driver through means of an electricindicator system. The visible portion of the indicator system isillustrated as an electric light bulb 2| housed in a casing 22 fixed tothe instru ment board. One terminal 23 of the incandescent wire 1 in thelight bulb is connected in parallel with the engine electric ignitionsystem 24 by conductor 20 and the other terminal 25 of the bulb wire 1is connected with a stationary contact 21 by conductor 26. Thisstationary contact 21 can .be fixed to a dielectric bracket 40 anchoredto a boss 30 formed on one of the interior walls 18 in the engine casingby securing bolts 8. The light circuit is grounded by conductor 31 thatcan be fastened to wall 19 and is controlled by means, in the form of amovable switch structure, that is responsive to temperature andpressure, preferably that of the oil in the pressure side of thelubricating system.

The control means for the light circuit consists of the ignition switch50 and a Bourdon tube 29 anchored at one end to wall l9 and having acontact 28 carried by and movable with the other end which is free. Thetube has an open inlet end 34 seated in a passage 31 in boss 30 andconduit 35 is attached to the boss, in communication with the passage,by fittin 38. Conduit 35 leads from the oil distributing manifold I8 onthe pressure side of the lubricating system. The free end of the Bourdontube is formed with a relatively small outlet opening 36 through whichoil flows into the engine casing and drains back into the sump, theoutlet opening being materially smaller than the inlet opening. formedof two welded together, flexible metal sections 32 and 33 havingdiiferent coeflicients of expansion.

Oil from the pressure side of the lubricating system will flow throughthe flexible Bourdon tube and the free end of the tube carrying thecontact 28 can flex in response to pressure and temperature of the oilto thus make and break the light circuit. The arrangement is such that,with the ignition switch 511 closed, the tube will be in circuit closingposition under normal engine operating conditions. When the oil supplyis low or other conditions occur in the engine operation that lower thepressure and/or raise the term perature of the oil, then the free end ofthe tube flexes in the direction shown by dotted lines in Fig. 2, andmoves contact 28 away from contact 21. Under this condition theindicator light goes out so that the driver will be advised of anunfavorable engine operating condition and will investigate. Under mostunfavorable engine operating conditions the oil pressure will decreasewhile the oil temperature rises and both pressure and temperature willinfluence flexing of the free end of the circuit control tube,

It will be understood that various forms of the invention other thanthat described above may be used without departing from the spirit or sOf the invention.

What is claimed is:

The tube is,

1. In an electric indicator system for a pressure lubricating systemhaving a stationary contact connected with a source of energy, a Bourdontube having an anchored end with an inlet opening communicating with thelubricatin systern, means grounding the tube, and a contact fixed to thefree end of said tube for engaging the stationary contact, the free endor said tube having a lubricant outlet orifice therein materiallysmaller than the inlet opening and flexing in one direction relative tothe stationary contact in response to high temperature or low pressureof the lubricant passing therethrough and in the other direction inresponse to low temperature or high pressure of the lubricant passingtherethrough;

2. In an indicator lightin circuit, a stationary contact in the circuit,a flexible Bourdon tube having an inlet opening at one end and an outletopening at the other end of much smaller diameter than the inletopening, means anchoring and grounding the inlet end of the tube, acontact fixed to the free outlet end of the tube and adapted to engagewith the stationary contact, and a source of fluid under pressureconnected with the anchored inlet end or the tube. the free end of saidtube flexing in one direction in response to low pressure or hightemperature of the fluid passing therethrough to control the relation ofthe contacts.

3. In an indicator circuit, a stationary contact, a tube formed oflongitudinally extending sections having different coefficients ofexpansion, said tube having an inlet opening at one end and a relativelysmall outlet openin at the other end, the inlet end of said tube beinganchored and grounded, and a contact fixed on the free end of the tube.

4. In an indicator circuit for a pressure lubricating system, astationary contact, a bimetallic tube having an inlet end with arelatively large opening connected with the lubricating system and arelatively small opening at the free outlet end, grounded meansanchoring the inlet end of the tube, and a contact on the outlet end ofthe tube, the outlet end of said tube reacting in one direction to lowpressure or high temperature of the fluid passing therethrough and inthe other direction to low temperature or high pressure of the lubricantpassing therethrough.

PIERRE STUART DE BEAUMONT.

